87311729 has 4 divisors (see below), whose sum is σ = 87467376. Its totient is φ = 87156084.

The previous prime is 87311701. The next prime is 87311743. The reversal of 87311729 is 92711378.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 87311729 - 2²⁰ = 86263153 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 87311692 and 87311701.

It is not an unprimeable number, because it can be changed into a prime (87311789) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 76979 + ... + 78104.

It is an arithmetic number, because the mean of its divisors is an integer number (21866844).

Almost surely, 2^87311729 is an apocalyptic number.

It is an amenable number.

87311729 is a deficient number, since it is larger than the sum of its proper divisors (155647).

87311729 is a wasteful number, since it uses less digits than its factorization.

87311729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155646.

The product of its digits is 21168, while the sum is 38.

The square root of 87311729 is about 9344.0745395143. The cubic root of 87311729 is about 443.6333597027.

The spelling of 87311729 in words is "eighty-seven million, three hundred eleven thousand, seven hundred twenty-nine".